Ancient DNA samples could help untangle the history of Homo naledi, writes Jennifer Raff from the University of Kansas at the Guardian.
H. naledi was only uncovered recently in a cave in South Africa and, with the finding of a second, younger H. naledi sample, it has upended what researchers have known about hominid evolution, she writes. As Raff notes, researchers have thought that hominin evolution generally led to organisms with bigger brains, longer legs, and smaller teeth, among other traits. But the newer, younger H. naledi sample has primitive as well as derived features.
There are a number of possible explanations for how H. naledi fits into the tree of hominin evolution — it could, for instance, belong to the lineage that also includes H. habilis and H. floresiensis or it could be the result of hybridization between different hominid lineages, among other scenarios, she notes.
The easiest way to determine which occurred would be by sequencing its DNA, but samples have been hard to come by, Raff says. "Will we ever get a H. naledi genome? Based on the hints we've gotten so far, the odds don't look great," she writes. "Just as with H. floresiensis … their position in our family tree looks to remain unclear for a while — a lesson to us about how much we still have to learn."